2. Cadmus, a straw, or culin, fig. 10, is the peculiar stem of grasses, rushes, and such like plants. It bears both leaves and flowers, and in that respect comes under the denomination of a caulis ; but is readily known by its habit, though difficulties at tend its definition. In most grasses, corn, &c. it is jointed in a manner peculiar to it self, and then cannot be mistaken ; but in common rushes, and some few grasses, it is destitute of joints. When these parts are bent, it is called geniculate, and such joints readily take root.
3. Scopus, a stalk, fig. 11, springs im mediately from the root, bearing flowers and fruit, but not leaves, as in the prim ' rose and cowslip. It is either simple or branched, naked or scaly. In the cycla men it becomes spiral after flowering, and buries the seeds in the ground. Dr. Smith has found, contrary to the opinion of Linnaeus, that a plant may sometimes be increased by its scapus, as in lachena dia tricolor, which occasionally bears bulbs • on its stalk.
4. Pedunculus, the flower-stalk, fig. 12.
springs from the stem or branches, bear ing flowers and fruit, but not lea\ es. Pe dicellus is a partial flower-stalk, or, in other words, the ultimate subdivision ofa gene ral one. The most common situation of a flower-stalk is axillary, originating from between a leaf and the stem, or between a branch and the latter. It is rarely op posite to a leaf, as in some species of geranium, and still more rarely interme diate between two leaves, as in some kinds of solanum. It is either terminal or lateral ; solitary, clustered, or scattered ; simple or branched. According to the
various modes in which it is subdivided, several kinds of inflorescence are distin guished, to be mentioned hereafter. Ses sile flowers are such as have no stalk. The flower-stalk is occasionally naked, or furnished with bracteas. Very rarely it bears tendrils.
5. Petiolus, the foot-stalk, fig. 13, is ap plied exclusively to the stalk of a leaf, and is either simple, as in all simple leaves, or compound, as in the greater part of compound ones. Sometimes it bears tendrils. It is generally channelled on the upper side, and more or less di lated at the base ; in one or two instances the flower-stalk grows out of it, as in tur nera. Leaves that have no foot-stalk whatever are called sessile. The sap-ves sels are for the most part very conspicu ous in foot-stalks, and their spiral coats are easily observed.
5. Ferns, a frond. This term, which properly means a bough, is technically applied by Linnxus to express the stem, leaf, and fructification being united, that is, the leaf bears the flowers and fruit. The term is only used in the class Cryp togamia. Ferns which bear seeds on the back of their leaf are genuine instances' of this, and it is applied to lichens, &c. Plate II. fig. 14.
7. Stipee, stiim, is the stem of a frond, fig. 15, or the stalk of a fungus, as in the common eatable mushroom. In the for mer instance it is very generally clothed with scales of a peculiar chaffy texture ; in the latter it is very often invested by a ring, formed of the membrane which had previously covered their fructifica tion.